ANDRITZ systems for turning trash into value
Reject treatment systems for paper mill waste
Converting industrial waste into valuable resources and energy
Every recycled fiber line needs a proper water, sludge handling, and reject system in order to operate economically. The goal is to minimize losses of process materials, recover and conserve resources (fiber, water, and energy), and minimize waste disposal.
In addition, many rejects can be valuable and even generate income for a mill: for example metals as raw materials and plastics as a source of energy. Rejects from recycled fiber processes are worthy of optimum and properly adapted treatment to extract their full value. The processes must be cost-efficient and simple, as well as fulfilling certain requirements to ensure that the rejects can become fuel (e.g. combusted), can be sold or re-used (e.g. pelletized), or can be disposed of at minimum cost and effort. This requires knowledgeable handling of the reject and a thorough knowledge of the individual process steps.
Typical paper mill, industrial waste sources
- Pulper rags
- Loose pulper rejects – containing mainly plastics, metals, stones, wood particles, etc.
- Sand containing cleaner rejects
- Light weight rejects from the coarse screening
- Rejects (e.g. pins, screening rejects) from BCTMP and TMP plants
- Bark and residuals from wood yard handling
- Thinning wood and residual material from forestry
Benefits of reject treatment systems
- Compliance with the legal requirements for protection of the environment, e.g. landfill directives
- Reduction of disposal and transportation costs up to 30%
- Pre-treatment of rejects for fuel generation
- Reduction of greenhouse gas emissions (CO2) from 25% to over 40%
- Additional income from recycling of raw material, e.g. metals or plastics